Assistance with Medal for 1,500th Anniversary of Conversion of St. Augustine

I found this medal in a group of coins (nice group--included Crete and Kiau Chau) I purchased some time ago. Your assistance would be appreciated.

It is silver; 30 mm; and weighs 17.9 grams.

It is apparently for the 1,500th anniversary of the conversion of St. Augustine (387-1887); and may have been issued by the Order of Saint Augustine.

It says "MANILA" below the coats of arms--but is this where it was issued?

http://www.elfreeman2.com/t18/augo.jpg

http://www.elfreeman2.com/t18/augr.jpg

propably this cathedral:
https://en.wikipedia.org/wiki/San_Agustin_Church_(Manila)
conversion:
https://www.scribd.com/document/209173404/S-Lourdunathan-on-St-Augustine-Conversion
The hat on the arms is the sign of a bishop:
https://en.wikipedia.org/wiki/File:CoA_Francis_de_Sales.svg

Thank you for the info.